1. Technical Field
The present invention relates to an active matrix substrate, a method of manufacturing the active matrix substrate, an electro-optical device, and an electronic apparatus.
2. Related Art
With the spread of portable apparatuses such as notebook computers and cellular phones, thin and light liquid crystal display devices are widely used. Such liquid crystal display devices have a liquid crystal layer interposed between an upper substrate and a lower substrate.
An example of the lower substrate (an active matrix substrate) is shown in FIG. 17. As shown in the figure, the lower substrate 1 includes a glass substrate 2, gate scanning electrodes 3 and source electrodes 4 disposed on the glass substrate 2 to intersect each other, drain electrodes 5 disposed on the glass substrate 2, pixel electrodes (ITO) 6 connected to the drain electrodes 5, insulating layers 7 disposed between the gate scanning electrodes 3 and the source electrodes 4, and TFTs (thin film transistors) made of thin semiconductor material.
For example, as disclosed in Japanese Patent No. 3261699, a technique of repeatedly performing a process in which a dry process and photolithography etching are combined is used for forming metal wires in the lower substrate 1.
A liquid droplet ejecting method is used for forming the drain electrodes 5 and the like in the active matrix substrate described above. That is, the drain electrodes 5 are formed by applying a conductive material between the TFTs 8 and the pixel electrodes 6 with a liquid droplet ejecting apparatus and solidifying the conductive material.
A semiconductor film constituting the TFTs 8 is subjected to a dewatering treatment and thus the semiconductor film and the pixel electrodes 6 have a height difference (the semiconductor film is higher than the pixel electrodes 6). As a result, when the conductive material is applied between the TFTs 8 and the pixel electrodes 6, the conductive material applied onto the semiconductor film flows out toward the pixel electrodes and thus the thickness of the drain electrodes 5 formed on the semiconductor film is reduced, thereby causing a problem that conductivity is deteriorated.